When she lost the nomination, he supported then-Sen. Barack Obama -- ardently. "I voted for Obama, I made donations, I had phone banks, I set up at condominiums and (sent) thousands of emails," said Barr, a 74-year-old south Florida resident. "By the third year, I realized I made a humongous mistake."

The next election, he voted for Republican nominee Mitt Romney as a rejection of Obama's policies toward Israel. And as the 2016 election nears, Barr has no plans to vote for Clinton, the Democratic front-runner.

Republicans have seized on Obama's rocky relationship with Israeli Prime Minister Benjamin Netanyahu, who has publicly clashed with the President over Iran and the Palestinians, to argue that Obama has not been a strong ally of the Jewish state. And they're extending that criticism to Clinton, who carried out Obama's policies for four years in her role as his secretary of state.

Though Jews overwhelmingly vote Democrat, conversations with Jewish voters at Ben's Kosher Delicatessen in Boca Raton suggested the GOP strategy is more than just wishful thinking. Patrons expressed deep dissatisfaction with Obama's dealings with Israel, and those feelings have tainted their impression of the former New York senator, who won Florida's Jewish voters 2-to-1 over Obama in the 2008 primary.

Hal Silverman, a 78-year-old Brooklyn transplant who's lived in Boca Raton for the last 25 years, was one of those Democrats who voted for Obama in 2008 and 2012. In the latter contest, the President won the county -- Palm Beach -- by 17 points, thanks in part to the Jewish vote; the county has the fourth-highest number of Jews in the country.

"I've always voted straight Democratic Party unless I particularly knew one or two of the people running who weren't Democrats who were better for the community," he explained on a sunny Friday outside Ben's, where CNN spoke with a dozen Jewish voters about Clinton and the 2016 election.

Disaffection over Middle East policy

But U.S. policy under Obama toward Israel and Iran has turned Silverman off from the President.

And from Clinton: "Absolutely, absolutely," Silverman said.

Ellen and Bob Hausner, a married couple of nearly 30 years divided along party lines, said they have finally found a point of agreement -- or mutual disapproval -- on politics. (Hint: She's a pantsuit aficionado and the leading Democratic candidate for president.)

"I would say a lot of people are disenchanted with the Democratic Party. People down here in particular," said Ellen, the Democrat in the family. "They have issues with the Iran deal now. They have issues with what's happening domestically, and they just have lost confidence and respect in Obama. And I don't think they're particularly supportive of Hillary."

Bob, a Republican, gleefully eyed his wife in agreement.

Photos:Hillary Clinton's life in the spotlight

Photos:Hillary Clinton's life in the spotlight

Hillary Clinton accepts the Democratic Party's nomination for president at the Democratic National Convention in Philadelphia on July 28. The former first lady, U.S. senator and secretary of state was the first woman to lead the presidential ticket of a major political party.

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Before marrying Bill Clinton, she was Hillary Rodham. Here she attends Wellesley College in Massachusetts. Her commencement speech at Wellesley's graduation ceremony in 1969 attracted national attention. After graduating, she attended Yale Law School.

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Rodham was a lawyer on the House Judiciary Committee, whose work led to impeachment charges against President Richard Nixon in 1974.

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In 1975, Rodham married Bill Clinton, whom she met at Yale Law School. He became the governor of Arkansas in 1978. In 1980, the couple had a daughter, Chelsea.

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Arkansas' first lady, now using the name Hillary Rodham Clinton, wears her inaugural ball gown in 1985.

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The Clintons celebrate Bill's inauguration in Little Rock, Arkansas, in 1991. He was governor from 1983 to 1992, when he was elected President.

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Bill Clinton comforts his wife on the set of "60 Minutes" after a stage light broke loose from the ceiling and knocked her down in January 1992.

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In June 1992, Clinton uses a sewing machine designed to eliminate back and wrist strain. She had just given a speech at a convention of the International Ladies' Garment Workers Union.

Clinton accompanies her husband as he takes the oath of office in January 1993.

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The Clintons share a laugh on Capitol Hill in 1993.

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Clinton unveils the renovated Blue Room of the White House in 1995.

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Clinton waves to the media in January 1996 as she arrives for an appearance before a grand jury in Washington. The first lady was subpoenaed to testify as a witness in the investigation of the Whitewater land deal in Arkansas. The Clintons' business investment was investigated, but ultimately they were cleared of any wrongdoing.

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The Clintons hug as Bill is sworn in for a second term as President.

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The first lady holds up a Grammy Award, which she won for her audiobook "It Takes a Village" in 1997.

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The Clintons dance on a beach in the U.S. Virgin Islands in January 1998. Later that month, Bill Clinton was accused of having a sexual relationship with former White House intern Monica Lewinsky.

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Clinton looks on as her husband discusses the Monica Lewinsky scandal in the Roosevelt Room of the White House on January 26, 1998. Clinton declared, "I did not have sexual relations with that woman." In August of that year, Clinton testified before a grand jury and admitted to having "inappropriate intimate contact" with Lewinsky, but he said it did not constitute sexual relations because they had not had intercourse. He was impeached in December on charges of perjury and obstruction of justice.

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The first family walks with their dog, Buddy, as they leave the White House for a vacation in August 1998.

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President Clinton makes a statement at the White House in December 1998, thanking members of Congress who voted against his impeachment. The Senate trial ended with an acquittal in February 1999.

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Clinton announces in February 2000 that she will seek the U.S. Senate seat in New York. She was elected later that year.

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Clinton makes her first appearance on the Senate Environment and Natural Resources Committee.

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Sen. Clinton comforts Maren Sarkarat, a woman who lost her husband in the September 11 terrorist attacks, during a ground-zero memorial in October 2001.

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Clinton holds up her book "Living History" before a signing in Auburn Hills, Michigan, in 2003.

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Clinton and another presidential hopeful, U.S. Sen. Barack Obama, applaud at the start of a Democratic debate in 2007.

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Obama and Clinton talk on the plane on their way to a rally in Unity, New Hampshire, in June 2008. She had recently ended her presidential campaign and endorsed Obama.

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Obama is flanked by Clinton and Vice President-elect Joe Biden at a news conference in Chicago in December 2008. He had designated Clinton to be his secretary of state.

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Clinton, as secretary of state, greets Russian Prime Minister Vladimir Putin during a meeting just outside Moscow in March 2010.

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The Clintons pose on the day of Chelsea's wedding to Marc Mezvinsky in July 2010.

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In this photo provided by the White House, Obama, Clinton, Biden and other members of the national security team receive an update on the mission against Osama bin Laden in May 2011.

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Clinton checks her Blackberry inside a military plane after leaving Malta in October 2011. In 2015, The New York Times reported that Clinton exclusively used a personal email account during her time as secretary of state. The account, fed through its own server, raises security and preservation concerns. Clinton later said she used a private domain out of "convenience," but admits in retrospect "it would have been better" to use multiple emails.

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Clinton arrives for a group photo before a forum with the Gulf Cooperation Council in March 2012. The forum was held in Riyadh, Saudi Arabia.

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Obama and Clinton bow during the transfer-of-remains ceremony marking the return of four Americans, including U.S. Ambassador Christopher Stevens, who were killed in Benghazi, Libya, in September 2012.

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Clinton ducks after a woman threw a shoe at her while she was delivering remarks at a recycling trade conference in Las Vegas in 2014.

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Clinton, now running for President again, performs with Jimmy Fallon during a "Tonight Show" skit in September 2015.

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Clinton testifies about the Benghazi attack during a House committee meeting in October 2015. "I would imagine I have thought more about what happened than all of you put together," she said during the 11-hour hearing. "I have lost more sleep than all of you put together. I have been wracking my brain about what more could have been done or should have been done." Months earlier, Clinton had acknowledged a "systemic breakdown" as cited by an Accountability Review Board, and she said that her department was taking additional steps to increase security at U.S. diplomatic facilities.

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U.S. Sen. Bernie Sanders shares a lighthearted moment with Clinton during a Democratic presidential debate in October 2015. It came after Sanders gave his take on the Clinton email scandal. "The American people are sick and tired of hearing about the damn emails," Sanders said. "Enough of the emails. Let's talk about the real issues facing the United States of America."

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Clinton is reflected in a teleprompter during a campaign rally in Alexandria, Virginia, in October 2015.

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Clinton walks on her stage with her family after winning the New York primary in April.

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After Clinton became the Democratic Party's presumptive nominee, this photo was posted to her official Twitter account. "To every little girl who dreams big: Yes, you can be anything you want -- even president," Clinton said. "Tonight is for you."

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Obama hugs Clinton after he gave a speech at the Democratic National Convention in Philadelphia. The president said Clinton was ready to be commander in chief. "For four years, I had a front-row seat to her intelligence, her judgment and her discipline," he said, referring to her stint as his secretary of state.

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Clinton arrives at a 9/11 commemoration ceremony in New York on September 11. Clinton, who was diagnosed with pneumonia two days before, left early after feeling ill. A video appeared to show her stumble as Secret Service agents helped her into a van.

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Clinton addresses a campaign rally in Cleveland on November 6, two days before Election Day. She went on to lose Ohio -- and the election -- to her Republican opponent, Donald Trump.

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After conceding the presidency to Trump in a phone call earlier, Clinton addresses supporters and campaign workers in New York on Wednesday, November 9. Her defeat marked a stunning end to a campaign that appeared poised to make her the first woman elected US president.

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Sitting inside the deli after eating what he called "the finest pastrami," Eugene Rudoy said his 2008 support for Hillary Clinton is no barometer of his feelings on the 2016 race.

"If you bring me to today, I wouldn't support her," the 84-year-old Boyton Beach resident said. "She's just an extension of Obama."

Clinton is already working to fight that perception when it comes to Israel, cognizant of Jewish voters' distrust of Obama's policies toward Israel and Iran.

While Clinton backs Obama's Iran deal -- which Israel opposes -- the former secretary of state, who helped launch the negotiations, committed to ensuring Israel's security and to confronting Iranian aggression in the same breath as she announced her support for the deal in September.

And in a letter to several top Jewish donors and pro-Israel leaders this summer, Clinton expressed her staunch opposition to calls to boycott Israel and pledged to fight the boycott movement.

The Clinton campaign on Thursday dismissed any concern that its support among Jewish voters could be in jeopardy.

Clinton touts support for Israel

Clinton campaign spokesman Jesse Lehrich touted her "commitment to our unshakeable alliance with Israel," citing her work to promote security cooperation with Israel and brokering a ceasefire that ended clashes between Israel and Hamas in 2012.

"Hillary Clinton has always had a deep connection to Jewish-American voters, and she is honored to continue to have strong support from that community," Lehrich said in an email to CNN. "She's made clear that continuing to strengthen this partnership will be a top priority of her presidency. For her, this goes beyond policy; it's personal."

Despite talk of a slide in Jewish support for the Democratic Party since Obama's election in 2008, Jewish voters still turned out in droves for Obama in 2012. Obama's share of the Jewish vote slipped to 69% from 74%, based on exit polling, a fall that mimicked drops among other typically pro-Democratic voting blocs.

Though Jews make up about 2% of the national population, they comprised 5% of voters in Florida that year, also according to exit polls. While still a small fraction of the total, every vote in the crucial battleground state is hotly contested. Florida's Jewish population also tends to be older and less progressive than Jews in many other parts of the country, making them more inclined toward hawkish positions on the Middle East.

Kenneth Wald, a political science professor at the University of Florida who has studied the Jewish vote throughout his career, said that while there's a clear "unease" about Obama's policies toward Israel among American Jews, he would "be surprised if that crystallizes into a significant political shift."

"For as long as I've been studying Jewish voters, people keep telling me this is the year we're going to see the transformation," he said. "I just think that this is stuff that happens between elections and the atmosphere changes when you actually get into choice."

And the Clintons, he said, still enjoy "a very deep well of attachment" among Jewish voters.

Unfortunately for Clinton, though, her staunchest supporter outside the Boca Raton delicatessen last Friday refused to be named for fear that her friends would mistakenly think she's anti-Israel.

"A lot of my friends, family -- some of whom are Democrats -- do not feel that Obama is for Israel. It's plain and simple," she said.

She said she was not concerned "at all" about the strength of Clinton's support for Israel and said that while she waffles on whether the Iran deal is good, she is hopeful it will result in a peaceful outcome.

She also hopes that one of her own reasons for supporting Clinton will resonate with fellow Jewish voters.

"People know the Clintons and I think that that will reign over anything else," she said. "You know, voting for Hillary is voting for two presidents, not one president. So you're getting two for the price of one. And a lot of Jewish voters loved Bill."